Switch unit



A. VENDITTY SWITCH UNIT Dec. 20, 1949 3 Sheets-Sheet 1 Original FiledAug. 23, 1943 FIE-3 INVENTUR NTHONY lE/VD/TTY G 6, W 9 vw/ X 8. W V m.wwu PM! II 2 @Q mm m Dec. 20, 1949 A. VENDITTY 2,491,696

SWITCH UNIT Original Filed Aug. 23, 1943 3 Sheets-Sheet 2 FIG 4 3/ /2.99 3 FIG 7 59 99 99 17 67 /o/ mo 3 26 47 a INVENTOH ANTHONY l E/w/rryDec. 20, 1949 VE 2,491,696

. SWITCH UNIT Original Filed Aug. 23, 1943 3 Sheets-SheetS INVEN T U M/THO/V) l/f/val T r BY Z fl/ WATTYS Patented Dec. 20, 1949 SWITCH UNITAnthony Venditty, Detroit, l'iich assignor to Thompson Products, Inc.,Cleveland, Ohio, a

corporation of Ohio Original application August 23, 1943, Serial lilo.

Divided and this application October 27, 1945, Serial No. 625,052

Claims. (Cl. 200 6) This invention relates to a switch unit and moreparticularly to a simple, compact reliable switch structure which isparticularly suitable for use in controlling electric motors onequipment used or installed in the home.

This application is a division of my copending application entitledSwitch unit, U. S. Serial No. 499,604, filed August 23, 1943, andassigned to the same assignee as the present invention.

One of the principal features and objects of the present invention is toprovide a novel compact switch unit for controlling the flow of highvoltage current such, for example, as the current usually supplied bypublic utility companies at 110 to 120 volts, 60 cycle A. C.

A further object of the present, invention is to provide a novel switchstructure housed in a single compact assembly.

Another object of the present invention is to provide a novel switch andmounting therefor which is economical to manufacture and which is ruggedand reliable in use.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the appended claims. My inventionitself, however, both as to its organization and manner of construction,together with further objects and advantages thereof, may best bunderstood by reference to the following description taken in connectionwith the accompanying drawings, in which:

Figure 1 is a diagrammatic view of a switch unit embodying the novelteachings and characteristics of the present invention and showing itwith a motor which it is designed to control and a pushbutton switchwhich efiects operation of the main switch unit, the switch unit beingcomplete and assembled except that the sealing compound is removed fromthe grooves in the cover;

Figure 2 is a plan view of the switch unit shown in Figure 1;

Figure 3 is a bottom view showing the under side of the cover which hasbeen removed from the switch unit;

Figure 4 is a sectional view of the unit as shown in Figure 2 as takenalong the line IV--1V thereof with the cover now in place;

Figure 5 is a sectional view of the unit with the cover in place astaken along the line VV of Fi ure Figure 6 is a section view of the unitwith the cover in place as taken along the line VI VI 0! Figure 2;Figure '7 is a sectional view of the upper portion of the unit with thecover in place as taken along the line VII-VII of Figure 2;

Figure 8 is an isometric view of the solenoid bracket;

Figure 9 is a plan view of the upper housing member of the unit; and

Figure 10 is a diagrammatic illustration of an electric circuit in whichthe novel switch of the present invention may be employed, and indicatesthe utility of the switch structure.

In order to understand the problem involved. and in order to fullyappreciate one of the useful circuits in which the novel switchstructure of the present invention may be used, reference will first bemade to Figure 10 of the drawings, wherein is diagrammaticallyillustrated a splitphase induction motor I I which is arranged to beenergized from supply conductors l2 and I3. Supply conductors l2 and iiiare arranged to be connected to a suitable source of alternating currentsupply, such, for example, as the conventional 110 volt 60 cycl currentwhich is usually supplied by the public utility companies throughout thecountry. The motor II has four terminal connections which have beenlabeled R, G, O and B. Although not shown, it will be understood bythose skilled in the art that the terminal connections R and B areconnected to one winding of the split phase induction motor ll while theterminal connections G and O are connected to the other winding, thelatter having a resistance element in series therewith.

Ihe motor I l is connected to supply conductors i2 and I3 through aswitch Hi. This switch ll has six stationary contacts IE to 20,inclusive, and three movable contact bars 2|, 22 and 23 which arecarried on a bar of insulating material 24 and arranged to be rockedabout the longitudinal axis of this bar. The contact bar 2| is arrangedto be rocked into engagement with either stationary contact l5 orstationary contact l8. Contact bar 22 is arranged to be rocked intoengagement with either stationary contact It or stationary contact l9.Contact bar 23 is arranged to be rocked into engagement with eitherstationary contact I! or stationary contact 20. Contact bars 2| and 22are connected together by bus 25 and to supply conductor l3 throughconductor 25. Contact bar 23 is connected to supply conductor |2 throughconductor 21.

Stationary contacts i5 and II are electrically connected together and toterminal B of motor through conductor 28. Stationary contacts l6 and 20are electrically connected together and are also connected to terminal Oof motor I I through conductor 29. Stationary contacts I! and I9 areelectrically connected together and are also connected to terminal G ofmotor through conductor 30. The terminal R of motor II is directlyconnected to supply conductor |2 through conductor 3|.

It will be understood by those skilled in the art that when theinsulating bar 24 is rocked in a counterclockwise direction as shown inFigure 10 of the drawings, movable contact bars 2|, 22 and 23 will bemoved into engagement with stationary contacts l8, l9 and and the motorwill operate in one direction. When the insulating bar 24 is rockedabout its longitudinal axis in a clockwise direction, movable contactbars 2|, 22 and 23 will be moved into engagement with stationarycontacts I5. l5 and I1, and the motor will be operated in the otherdirection.

The control and operating circuit for rocking the bar 24 includes a pairof solenoids 3| and 32 and a step down transformer 33. Transformer 33includes a primary winding 34 and a secondary winding 35. The winding 34is connected across the supply conductors l2 and i3 as shown. The ratioof the number of turns in the secondary winding 35 to the number ofturns in the primary winding 34 is such that current at low voltage issupplied through conductors 35 and 31. It is preferable that the currentsupplied through conductors 35 and 3'! have a voltage of between 6 to 10volts.

Conductor 36 is connected to one end of the solenoid 3| and also to oneend of thesolenoid 32. The opposite end of solenoid 3| is connected to aswitch contact 38 through conductor 33 while the opposite end ofsolenoid 32 is connected to a switch contact 40 through conductor 4|.Two additional contact elements 42 and 43 are provided which areassociated with contacts 38 and 40 respectively and which are connectedthrough conductor 31 to the lower end of secondary winding 35 oftransformer 33. Contacts 38 and 42 are arranged to be closed by amovable switch element 44 while contacts 40 and 43 are arranged to beclosed by a movable contact element 45. Contact elements 44 and 45 arenormally biased to their open position.

Transversely mounted on the insulating bar 24 is an armature arm 45which is made of iron or some other suitable magnetic material. When thecontact 44 is closed, solenoid 3| is energized from transformer 33 andthe left-hand portion of the armature 45 is pulled down, thus rockingthe bar 24 in a counter-clockwise direction about its longitudinal axis.On the other hand, if contact element 45 is closed, solenoid 32 isenergized and the right-hand portion of armature 4B is pulled down, thusrocking the bar 24 in a clockwise direction about its longitudinal axis.

The compact unitary nature of the invention is exemplified by theparticular physical embodiment illustrated in Figures 1 to 9 of thedrawings. In the form shown, a single closed housing l0 comprising lowerand upper housing members 41 and 48 are provided for the transformer 33,the solenoids 3| and 32 and the switch l4.

This housing, which is preferably formed of some suitable moldedmaterial of good insulating qualities, is so shaped as to provide atransformer compartment 43, a solenoid compartment 50 and a switchcompartment 5|. To this end, the lower housing member 41 has an upperwall portion 52 which extends entirely over the compartment 43.'Downwardly extending shoulders 53 and 54 are formed at either end ofthe wall portion 52 to provide a suitable seat for the laminated ironcore 55 of the transformer 33. The compartment 49'is further closed offby a panel 56 which extends across the lower open end of the housingmember 41. As is clearly shown in Figures 4 and 6, the end wall 51 istapered as at 53 and the wall portion 53 is tapered as at 50. Thispermits ready insertion of the transformer 33 through the lower openingin the housing member 41 when the panel 55 is removed.

The base wall 6| of the solenoid compartment 50 is slightly offset fromthe remaining base walls of the housing member 41 formed by the panel56. The solenoids 3! and 32 are mounted on a T-shaped iron bracket 52and secured by means of bolts 63 to the base wall portion 8|. Thesolenoids 3| and 32 are of conventional design and include iron cores 54and 55 respectively. The bolts 83 are threaded into the lower end ofthese iron cores 64 and 55 to thus secure the solenoids in place. Thebracket 52 has a cut-away portion 56 which forms a shoulder on which thearmature arm 46 is arranged to be seated (see Figure 8).

A C-shaped bracket is molded as an integral part of the upper wallmember 52 and includes a base portion 51 and two upstanding lips 68 and59. This bracket supports and confines the tongue 92 at one end of thebar 24 which carries the movable contact elements 2|, 22 and 23. Thearmature arm 45 is secured to the bar of insulating material 24 by abolt 33, and the central portion of arm 45 which extends beyond the endof bar 24 is slotted as at 34 (see Figure 2). This slotted portion 94 isarranged to receive the upstanding top portion 35 of the bracket 62,while the unslotted central portion of the arm 46 is arranged to beseated on the shoulder 55 of the bracket 52. The bar 24 is thus arrangedfor rock ing movement about its own longitudinal axis.

The bar 24 has three transverse grooves ii, 72 and I3 in the uppersurface thereof which are arranged to have metal contact arms 2|, 22 and23 seated therein. In the center of each groove ll, 12 and I3 9. pinprojects upwardly therefrom. More particularly, pins 14, I5 and 15extend through .the bar 24 as may be seen best in Figure 4'. Each of thecontact arms 2|, 22 and 23 is provided with a circular opening throughthe center which is slightly larger than the pin, as is indicated at I1,18 and 13 (see Figure 2). Since it is necessary to electrically connectcontact arms 2| and .22, a flat electrical connector 25 is seated on thesame, suitable apertures 96 being provided in the strip 25 to permit thepins 14 and 15 to extend therethrough. For a reason which will presentlybe apparent the strip 25 is also provided with an upstandingprotuberance 91 at its center.

The ends of the contact arms 2|, 22 and 23 are provided with contactbuttons which are arranged to engage the confronting buttons 8| on thestationary contacts I! to 20, inclusive. Due to the fact that theopenings 11, I8 and 19 in the contact arms 2| to 23 are somewhat largerthan the pins I4 to 14 it will be apparent that the contact arms 2| to23 may have limited rocking movement on the bar 24 about one or theother end of each of their associated grooves, depending upon whichdirection the bar 24 is rocked.

The bar 24 is resiliently held in place by a pair of coil springs 82 and83 which are seated in the recess portions 84 and 85 respectively of theupper housing member 48. The lower end of the coil spring 82 is seateddirectly on the contact strip 25 over the protuberance 91, while thelower end of the coil spring 83 extends over the pin 18 and is seated onthe contact arm 23.

It will thus be clear that not only is the bar 24- resiliently held inplace, but the contact arms 2|, 22 and 23 are also resiliently held intheir respective recessed seats on the bar 24.

The upper surface of the upper housing member 48 is provided with fourtransverse grooves 86, 81, 88 and 89 which are preferably of the shapeand configuration as illustrated in Figures 4, 6, 7 and 9 of thedrawings. As either end of each transverse groove 85 to 89, a copper orbrass bushing 98 extends through the wall of the upper housing member48. As is clearly shown in Figure 6 of the drawings, the bushings 98 ineach of the grooves 86, 81 and 88 are arranged to receive the stationarycontact buttons 8|. The upper end of each bushing 98 is threaded and setscrews 9| are threaded therein. Each of the two bushings 98 in the endgroove 89 is provided with a set screw 98 at the outer end and also aset screw 99 at the inner end.

The terminal set screws 98 are arranged to be connected to the A. C.supply conductors I2 and I8 (as shown diagrammatically in Figures 1 and10). The set screws 99 (which are electrically connected to screws 98through the bushings 98) clamp the ends of the conductors I88 and INleading from the primary 34 of the transformer. They also receive andclamp pigtail conductors 28 and 21 wh ch extend from contact arms 22 and23 respectively.

A partition wall I82 between grooves 81 and 88 in the upper housingmember 48 is broken out as at I83 to permit conductors I84 and I85 toextend therethrough. As shown in Figure 10, conductor I84 connectscontact buttons I1 and I9, while conductor I85 connects buttons I8 and28. Contact buttons I5 and I8 are connected together by a conductor I88which extends across the bottom of the groove 88.

Since the electrical connections between the motor II and the unit I8are designed to be permanent, the grooves 88 and 89 are preferablyfilled with an insulating compound of the type which hardens when cooledand forms a substantially permanent part of the housing member 48.

The upper and lower hous ng members 48 and 41 are secured together bybolts I81. A pair of feet I88 may be molded or otherwise formed in thelower housing member 41 to enable the unit to be secured in any desiredposition.

Low voltage push button switches 44 and 45 are preferab y contained in asmall separate housing I89, while the conductors 39. 4| and 31 whichconnect the push button switches 44 and 45 to the control circuit of themain switch contained in the unit I8 are preferably confined in a singlecable I I8. The conductors 39, 4| and 31 are connected respectively toguiding posts III, 2 and 3 on the exterior end wall 4 of the lowerhousing member 41. The electrical connections between the push buttonswitches 44 and 45 and the main unit I8 are arranged to be made by anyinexperienced person, and since only low voltage flows in this externalcircuit no professional electrician is required. The conductors 28, 29,38 and 3| which extend between the motor II and the unit I8 arepreferably contained in a well insulated cable 5. the connections atboth ends being made substantially permanent at the factory at the timethat the motor II and the unit I8 are assembled. Although relativelyhigh voltage flows through the conductors in the cable II5, it is notnecessary to have a professional electrician since nochange is to bemade in these connections at the time that the motor II- is installed..The alternating current power source is connected to the unit I8, aspreviously described, to conductors I2 and I3. These conductors I2 andI3 are preferably contained in a cable I I6 having a male plug member II1 at their ends which is arranged to be plugged into a conventionalvolt 60 cycle alternating current socket (not shown).

When the motor II and the unit I8 are installed in a position where themotor is to be used (such, for example, as in a private garage foroperating the main garage doors), the power supply cable I I6 is pluggedin by the male plug member 1 into a suitable outlet box. The box I89containing the push button switches 44 and 45 is then mounted any placedesired and a cable is run from the box I89 to the terminals III, 2 andN3 of the unit 8. When the push button switch 44 is depressed, thesolenoid 3| is energized and the bar of insulating material 24 is rockedin a counter-clockwise direction as viewed in Figure 10. This causes themovable contact arms 2|, 22 and 23 to engage the stationary contactbuttons I8, I9 and 28 respectively. Similarly, when the push button 45is'depressed rather than push button 44, solenoid 32 is energized andthe bar 24 is rocked in a clockwise direction about its own longitudinalaxis to cause the contact arms 2|, 22 and '23 to make an electricalcontact with their associated stationary contact buttons I5, I6 and I1respectively. Figure 5 shows the position of the movable contact arm 2|as it is moved into position against its associated stationary contactI5. It will be observed that not only is the bar 24 rocked in aclockwise direction about its longitudinal axis, but the arm 2| itselfhas a rocking movement with respect to the bar 24. This rocking movementof contact arm 2| with respect to the bar 24 is a relativecounterclockwise movement of the arm 2|. This causes a wiping actionbetween the contact button 88 on the end of the arm 2| over the contactbutton 8| which forms the stationary contact I5. Furthermore, due to thefact that the coil spring 82 tends to retain the contact arm 2I seatedfiat in its associated recess 1| in the bar 24, it will be apparent thatthe contact button 88 is held resiliently pressed against the contactbutton 8|. A similar action occurs between the other confronting contactbuttons upon movement of the bar 24 to one or the other of its extremepositions.

When both solenoids 3| and 32 are deenergized, the springs 8'2 and 83cause the bar 24 to remain in its intermediate position as shown inFigure 6.

While I have shown a particular embodiment of my invention, it will, ofcourse, be understood that I do not wish to be limited thereto, sincemany modifications may be made and I therefore contemplate, by theappended claims, to cover allsuch modifications as fall within the truespirit and scope of my invention.

I claim as my invention:

1. A switch unit comprising a supporting structure, an elongated membermounted on said supporting structure for rocking movement about itslongitudinal axis, two groups of stationary contacts on said supportingstructure on opposite sides of said elongated member, a plurality ofcontact arms seated in a transverse position on said elongated member,means for resiliently holding said contact arms in seated engagementagainst said elongated member, said contact arms being free to haverelative rocking movement about either side edge of said elongatedmember and against the resilient action of said means about an axisabove said elongated member, said contact arms and said two groups ofstationary contacts being positioned so that one group of stationarycontacts are engaged by said arms when said elongated member is rockedon its axis in one direction and the other group of stationary contactsare engaged by said arms when said member is rocked on its axis in theother direction, and means for rocking said elongated member.

2. A wiping contact pressure switch comprising supporting means, astationary contact on said means, a member pivotally mounted for rockingmovement on said means, a contact arm seated on said member, means forresiliently urging said arm in a straight line downwardly against saidmember, said arm having a contact portion arranged to engage saidstationary contact when said member is rocked, said contact arm beinginitially moved about the pivot axis of said member until said contactportion engages said stationary contact, and said contact arm thereafterhaving relative angular movement about an edge of said member andmovement in line with said resilient means against the resilient actionof said resilient means, whereby a wiping pressure contact is madebetween said contact portion and said stationary contact.

3. A double throw switch comprising supporting means, an insulatedmember mounted on said supporting means means and arranged for limitedrocking movement, a pair of stationary contacts disposed on oppositesides of said rocking member, said member having a surface presenting agenerally flat seat, a contact arm having contact portions at oppositeends arranged to engage said stationary contact, said contact arm beingseated on said seat, means providing a movable pivot for said contactarm above said seat, means resiliently urging said arm against saidseat, said pivot above said seat being movable in a line correspondingto the line in which said resilient means acts, and means for rockingsaid insulating member to selectively place one of said contact portionsof said arm in engagement with one of said stationary contacts, saidcontact arm being initially moved about the axis of rock of saidinsulating member by movement of the latter until one of said contactportions engages one of said stationary contacts, and said contact armthereafter having relative angular movement with respect to saidinsulating member about an edge of said seat surface and about saidmovable pivot, whereby a slidin pressure contact is made between saidcontact arm and said stationary contacts.

4. A switch unit comprising supporting structure, a member mounted onsaid supporting structure for pivotal movement, at least one stationarycontact on said supporting structure, at least one contact arm having anopening in the center thereof, a pin projectin from said memher andloosely receiving the opening in said contact arm for relative rockingmotion of the arm on said pin, means for resiliently holding saidcontact arm in seated engagement on said pin of said elongated memberand for permitting said relative rocking motion of the arm against theresilient opposition thereof, said contact arm being initially movedabout the pivot axis of said member until said arm engages saidstationary contact, and said contact arm thereafter having relativerocking movement about an edge of said elongated member as well as withrespect to said pin against the resilient opposition of said resilientmeans, whereby a wiping pressure contact is made between said contactarm and said stationary contact.

5. A compact switch unit comprising an insulating housing includingupper and lower housing members, an elongated member'mounted on saidlower housing member for rocking movement about its longitudinal axis,two groups of stationary contacts on said upper housing member onopposite sides of said elongated member, a plu rality of contact armsseated in a transverse position on said elongated member, means forresiliently holding said contact arms in seated engagement on saidelongated member, said contact arms being free to have relative rockingmovement about the side edges of said elongated member and against theresilient action of said means about said elongated member, said contactarms and said two groups of stationary contacts being positioned so thatone group of stationary contacts are engaged by said arms when saidelongated memberis rocked in one direction and the other group ofstationary contacts are engaged by said arms when said member is rockedin the other direction, and a low voltage switch operation mechanism forrocking said elongated member and disposed in said lower housing.

ANTHONY VENDIT'I'Y.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,559,110 Leddick Oct. 27, 19251,654,646 Hartwig Jan. 3, 1928 1,782,916 Campbell Nov. 25, 1,9301,796,449 Getchell Mar. 17, 1931 1,869,330 Anderson July 26, 19322,446,299 Nelsen Aug. 3, 1948

